Society of Naval Architects and Marine Engineers

SNAME Ad Hoc Panel #6

Tools Assessment Working Group (WG1 and former WG2, Data)

Last revised: April, 2000 (SNAME 2000 paper update)

Previous revisions:
January 6, 2000 (update on collision model progress)
October 24, 1999 (update on collision model progress, benchmarking and plan)
March 11, 1999 (added Virginia Tech Work Plan)
Sept 7, 1998 (created)

New
Objectives
Work Plan, Tasks and Methods
Deliverables
Scheduled Meetings
Grounding Model
Collision Model
Data Requirement
Additional Information and Related Links

References

WG1 Leader and WG1 Grounding Team Leader:
Dr. Kirsi Tikka
Webb Institute of Naval Architecture
Glenn Cove, Long Island, NY 11542-1398
Phone: 516-671-2356
Fax: 516-674-9838
e-mail: ktikka@webb-institute.edu
WG1 Collision Team Leader:
Dr. Alan Brown
Virginia Tech Department of Aerospace & Ocean Engineering
Blacksburg, VA 24061
Phone: 540-231-4950
Fax: 540-231-9632
e-mail: brown@aoe.vt.edu

New

Collision Benchmarking - The Fall 99 visit of Dr. Jeom Paik (Pusan National University) and Marie Lutzen (TDU) to Virginia Tech provides an excellent opportunity for collision collaboration. MIT has also provided their collision program, DAMAGE, for comparison and benchmarking. Our plan is to make a series of benchmarking and sensitivity runs comparing the results of these models with SIMCOL, the Virginia Tech / SNAME model. A series of test matrices will assess sensitivity to scenario parameters (speed, displacement, striking ship bow shape and stiffness, relative draft and depth, collision angle, striking location), struck ship structural design parameters (side shell thickness, deck and bottom thickness, web spacing, stringers) and struck vessel size. The IMO reference DH designs will be used for struck ships (60k dwt, 150k dwt and 283k dwt) with structural scantlings developed in SAFEHULL (Phase A). A validation run will also be made using a SH design and actual collision data. Latest information can be found in the SNAME2000 Paper Update.

Model Summaries

SIMCOL (VT/SNAME)

DTU (Technical University of Denmark)

DAMAGE (MIT)

ALPS/SCOL (Pusan National University)

Test Matrices

Matrix #1 and Results

Matrix #2 and Results

Matrix #3 and Results

Matrix #4

Struck Ships

60k dwt DH

150k dwt DH

283k dwt DH

SH Validation - Kuroiwa (1996)

Striking Ships

150K dwt Bulk Carrier

40K dwt Container Ship

20K dwt Container Ship - Kuroiwa (1996)

Collision Problem Definition - In parallel with the benchmarking studies, the work will assess the validity of uncoupling external dynamics, striking ship bow damage and struck ship side damage into 3 separate problems. This greatly simplifies and generalizes the solution.
Striking ship bow definition - LSDYNA is being applied to assess simplified methods for specifiying striking ship bow stiffness and shape. See: WG3.

Objectives

Investigate, compare and assess tools for predicting grounding and collision damage (including collision with ice). Emphasize simplified methods, which can be readily applied to the design and rapid analysis of new structural concepts, including applications using probabilistic scenarios. Finite element and other more rigorous methods may be considered and used to validate simplified methods, but are not appropriate for many rapid analyses required in concept design and probabilistic studies. Include comparisons to available data.

The Tools WG will also act as the integrator and test bed for products from the other WGs:

Data from the WG2 will be used by WG1 to assess and validate grounding and collision models and sub-models. WG1 will recommend data types and data format to WG2 necessary to support model validation.
Scenarios from WG3 will be calibrated and used by WG1 in the grounding and collision models. WG1 will recommend scenario inputs required for damage prediction.
Designs developed by WG4 will be assessed by WG1. WG1 and WG4 will work together to identify important design parameters to be included in the damage models.

Work Plan, Tasks and Methods

Material compiled by workgroup members will be posted on the workgroup web pages for comment and question throughout the work of the panel. Two teams will support these efforts: a Webb/MIT team will provide grounding model (pdf format) support; and a Virginia Tech team will provide collision model support: baseline collision model and VT work plan (pdf format). The Ship Structure Committee and SNAME are funding a portion of this effort including grounding and collision computer modeling and additional research necessary to integrate and test the WG products.

Work will follow an iterative process:

Team leaders - post material for other members to review and discuss.
WG members - provide comment, critique, alternative approaches, supporting or conflicting data, etc.
Team leaders - integrate feedback, model, assess, post feedback

Tasks and work plan events include:

Identify available methods for predicting grounding and collision damage.
Identify simplified methods and their range of applicability.
Collect results from previous studies (including finite element and other methods).
Discuss and integrate with other workgroups at the panel meeting during the SNAME Annual Meeting, November 1998.
Compare results obtained using simplified methods with results from studies based on rigorous analytical methods or model testing.
Present the results of Tasks 1, 2 and 3 and interim results of Task 4 in an Informal Panel Workshop SNAME Annual Meeting, October 1999.
Support other panel working groups.
Contribute to the panel paper for the SNAME Annual Meeting 2000.
Complete grounding and collision studies - January 2001.
Provide team papers for 2^nd International Conference on Designs and Methodologies for Collision and Grounding Protection of Ships, Spring 2001.

Additional Information and Related Links

http://www.sname.org/committees/tech_ops/O44/crashworthy/charter.html